This invention relates to absorbent materials adapted for use in body contact applications and, more particularly, to enzymatic absorbent materials such as bandages and pads that produce a bacteriostatic effect upon contact with body fluids such as serum.
Absorbent materials in the form of bandages and pads have long been employed in body contact applications where coverage and protection of a wound and absorption of its fluids are desirable. Bandaging can serve to physically protect an open wound from the surrounding environment, which is often replete with harmful bacteria, and to absorb fluid materials such as pus, blood and serum to thereby promote the healing of the wound. Accordingly, bandages are constructed of strong, yet absorbent, materials such that retention of extraneous fluids can be accomplished without a concommitant loss of strength.
Absorbent materials such as woven fibers, porous foam pads, absorbent membranes and solvent-based porous elastomers have been utilized in the manufacture of bandages and pads. A wide of variety of raw materials have been employed in an attempt to obtain physically occlusive structures that retain their strength when soaked with fluid from an open or weeping wound or other body fluid source. Materials such as cellulose and its derivatives (cellulosics), polyester, nylon, polyacrylamide, collagen, polyurethane and polyvinyl alcohol have been fabricated into structures such as woven fibers, foam pads, porous membranes, elastomers and multi-layered combinations of the aforementioned structures. Regardless of the material used, all bandages and pads employed in the protection of open wounds must satisfy the requirement of good absorbency in order to be effective.
An absorbent material in contact with an open or weeping wound will retain a substantial amount of blood, blood serum, pus and a variety of wound exudates. Bandages are often constructed in such a way that moisture retained by the absorbent material in contact with the wound will transpire through the side of the bandage opposite to that of the source of the fluids, i.e., the open wound. Although structures such as these tend to decrease the amount of moisture retained by the absorbent material, other exudates such as white blood cells, bacteria, eletrolytes, and red blood cells are retained. These exudates accumulate as a function of the amount of time an absorbent material is in contact with an open or weeping wound.
As a result of the retention of such a wide variety of biological substances, a moist absorbent structure can become an effective breeding ground for potentially harmful bacteria. Such an absorbent structure in contact with body fluid of the type mentioned above can be characterized as a culture support medium that can give rise to a large number of potentially harmful bacterial colonies in a relatively small volume. Since the accumulated bacteria and their waste products remain in contact with the open or weeping wound, they can leach out of the absorbent structure and back to the body. In this connection, symptoms classifiable as toxic shock syndrome have been associated with the use of certain types of feminine hygiene tampons, i.e., internally disposed feminine hygiene absorbent pads.
It would, of course, be advantageous to provide absorbent materials in the form of bandages, pads, strings and the like that would inhibit bacterial growth in body fluids which are absorbed by or otherwise associated with such absorbent materials or structures.
It is disclosed in the prior art that polymeric wound dressings for burns may include antibacterial agents, antibiotics, antifungal agents, proteolytic enzymes as well as local anesthetics, hormonal compounds and lubricating and barrier chemicals. See, for example, U.S. Pat. No. 4,122,158 (Schmitt, 1978) and U.S. Pat. No. 4,226,232 (Spence, 1980).
It is also disclosed in the prior art that enzymatic agents can be incorporated into oral products such as toothpaste and chewing gum for producing hydrogen peroxide during oral use.
U.S. Pat. No. 4,150,113 (Hoogendoorn et al., 1979) and U.S. Pat. No. 4,178,362 (Hoogendoorn et al., 1979) disclose, respectively, an enzymatic toothpaste and an enzymatic chewable dentifrice containing glucose oxidase which acts on glucose present in saliva and tooth plaque to produce hydrogen peroxide. The patentees note that oral bacteria, through enzymes systems having SH-GROUPS, effect glycolysis of food products containing sugars and point out that lactoperoxidase, which is present in saliva, provides the means for transferring oxygen from hydrogen peroxide to the oral bacteria resulting in the oxidation of the SH-containing enzymes into inactive disulfide enzymes. It is further disclosed that the dentifrice may be formulated with potassium thiocyanate.
U.S. Pat. No. 4,269,822 (Pellico et al., 1981) discloses an antiseptic dentifrice containing an oxidizable amino acid substrate and an oxidoreductase enzyme specific to such substrate for producing hydrogen peroxide and ammonia upon oral application of the dentifrice, with pre-application stability being maintained by limiting the quantity of any water present in the dentifrice.